Differing stack results

[xelasnave]

Ok I dont know what is going on and it is driving me crazy...

First I notice my data earlier data files are not 50 meg but only 4 meg...I only noticed as incompatiable file size turned up when stacking in DSS.

Ok I had set a small sensor size in Sharpcap which explains the small size for the first batch but I did nothing to change it up to 50 meg...

So start again...
Now I have a batch of subs (RASA and ZWO mono 2600) from the 1/9/2020 showing a size of 6248 x 4176...and a batch from 4/9/2020 showing a size of 6248 x 4176...that says same to me...

Now I stack each batch and no change in DSS setting and within minutes of each other...now the stack result is a file for 1/9/2022 ...5710 x 3347...but the stack for the 4/9/2022 produces a file 5749 x 3461....?????
And if I stack both batches from the two nights I get a stacked file of 5629 x 3296...
My questions..first is there something in Asiair Plus that changes sensor size as the change from small to large seems to have been automatic but maybe I did something to cause the change... happy with the change but why did it produce 4 meg images and later 50 meg???
Second what could be happening when I stack images of the same size to come out different sizes...is this why I still have hair so I can now pull it out in frustration...

Alex

[xelasnave]

This (link below) seems similar but I don't really know but it's a start I guess...and if someone is reading it is interesting to know about...

It took a couple of test shots today and they are a different size again to what came thru last night.

I will load Sharpcap and see what size is there and certainly set it for the largest file size...next format the thumb drive for the Asiair, and take some test subs to see the size...but it means that I have practically useless data on the Helix..I don't mind starting over which is where I was on 1/9/2022 AND happy to get all new data but the second night data although the same isn't?....
Alex

https://superuser.com/questions/1448465/exact-files-copied-have-a-different-size-on-disk-on-the-same-drive

[xelasnave]

I took the camera into Sharpcap and it was still on small sensor setting so I took it back to big but in Aisiair is is a little smaller than what I set it to in sharpcap...

I did a few tests switching off and on and so far at least the images are staying the same size.

All I can do is do some subs and see what happens in the next stack

alex

[oska]

Sounds more like a AA+ thing and not anything to do with the filesystem.
No AA+ experience though so no help there.

[Addos]

are you perchance using the 'intersection' output mode in dss? try standard. if youre stacking in separate batches make sure you have the same reference frame selected.

[xelasnave]

Thanks ...pretty sure same reference frame and yes to using intersection mode...thanks for trying to help...wo t be for a while but I will try again.
Alex

[The_bluester]

6248 x 4176 is the native resolution of the sensor in the 2600 and 50 meg is about the native file size for the full sensor at bin 1, 50,969KB right?

I have not used DSS for a long time but in Astro Pixel processor using default settings you will get a larger output frame than the input frames as the eventual output will be the smallest rectangle which covers all of the frames when they are star aligned so there is black space around edges (More or less from dithering)

The black space in the snip attached is included in the image dimensions that APP reports, and if I threw in more subs that are further out of alignment with the rest, the black space (And overall image dimensions) would be bigger again.

[Startrek]

Alex
Here’s some info on DSS which you may already have when I sent it last month

Just make sure you change the settings in DSS (Digital Development Raw Fits ) when swapping between your 2600MC and 2600MM
2600MC you must tick box that says Monochrome 16bit Fits from DSLR or OSC
2600MM you must uncheck or untick the box that’s days Monochrome 16bit Fits from DSLR or OSC

Also make sure in Sharpcap you select Bin 1x1 for your capture subs ( Use Startools to Bin your image )
Also use same Gain setting and cooling temp for all subs as well ( exposure times can differ if you want )

See attached

Hope this helps !

Cheers
Martin

[xelasnave]

Thank you gentlemen all I can do is wait and see how my next session turns out if that will ever happen...
Alex

[The_bluester]

That third image of Martin's is the equivalent to the APP setting I was thinking of where the stack is effectively cropped to the reference frame. I generally don't use that option in APP as I normally manually crop a little tighter than the reference frame anyway.

[xelasnave]

All I can think is I have bumped the crop is DSS.
There really is no other explanation...anyways I am onto a gallaxy and will come back to Helix and start over ...
I don't feel comfortable not nailing down the problem but I must live with that.
Thanks everyone.
Alex

[The_bluester]

Can you put up an uncropped image of the stack from DSS? There are telltales if it is a "Full" integration with the final image expanded to cover all the area contained by all subs and it should be pretty easy to see if that is what has happened.

[xelasnave]

I will look but I think I trashed all my data
Alex

[Addos]

The differing crops are because you are using intersection mode in DSS. Use standard and it will stack the output image in its native size. You then crop out the stacking artifacts manually.

I know it can be tedious, but it is really helpful to read the instructions provided with the software.



Keep in mind too, occam's razor is a thing for a reason :)

[xelasnave]

Thanks I have read the instructions many times and because I guess old age each time I do it is all fresh information...however I never picked up on what you point out...
Thanks I really appreciate your input.

I have not had the time to do any processing etc but it sounds like if I have not scraped the data there is a chance..

Alex